1. Field of the Invention
The present invention relates to a film deposition apparatus, a substrate processing apparatus and a film deposition method that perform a plasma treatment on a substrate.
2. Description of the Related Art
An ALD (Atomic Layer Deposition) method is known, for example, as one of the methods of depositing a thin film such as a silicon oxide film (i.e., SiO2) on a substrate such as a semiconductor wafer (which is called a “wafer” hereinafter), as disclosed in Japanese Patent Application Laid-Open Publication No. 2010-239102. In this apparatus, five wafers are arranged on a turntable in a circumferential direction, and a plurality of gas nozzles is arranged above the turntable. The apparatus deposits a reaction product on the wafers in a layer-by-layer manner by supplying a plurality of kinds of reaction gases that react with each other on the respective rotating wafers.
In such an ALD method, an apparatus is known that provides a member to perform the plasma modification at a position away from the gas nozzle in the circumferential direction to perform a plasma modification for the respective reaction product deposited on the wafers, as disclosed in Japanese Patent Application Laid-Open Publication No. 2011-40574. However, when a concave portion such as a hole or a groove (trench) having a high aspect ratio such as one more than tens or one hundred in a surface of the wafer, a degree of the modification may vary in a depth direction of the concave portion. In other words, when the concave portion with the high aspect ratio is formed, the plasma (which is more specifically, argon ions) is unlikely to go into the concave portion. Moreover, because the plasma treatment and the film deposition process are performed together in a vacuum chamber, a process pressure in the vacuum chamber is higher than a vacuum atmosphere in which the plasma can remain active preferably. Due to this, the plasma is likely to be deactivated when the plasma contacts an inner wall of the concave portion, which also causes the degree of modification to vary in the depth direction of the concave portion. Furthermore, even when the concave portion is not formed in the wafer, in order to perform the modification treatment while the turntable rotates one revolution, in other words, in order to preferably perform modification in a narrow area between gas nozzles adjacent to each other, high-density plasma needs to be formed in the vicinity of the wafer.
Japanese Patent Application Laid-Open Publication No. 8-213378 discloses an apparatus that applies a bias voltage to a lower electrode, but does not disclose a technique that rotates a wafer by using a turntable.